Alternator Bearing

[barryware]

I have searched the forum and found information in regards to corroded terminals and failing voltage regulators but nothing about replacing the front bearing on the alternator (2007 USA LB).

Has anyone replaced only the front bearing? Is the bearing pressed onto the stator shaft.. Are special tools required? Is the pulley keyed to the shaft or is it a taper lock?

Any info available on a source for the bearing? It seems the days of going to the auto parts store and getting just a bearing are over.

The alternator is fine electrically.. Just started making one heck of a racket.

I don't want to tear it down for inspection (how it is put together) without having the parts to put it back together.

In the past, I have been able to just re-pack a bearing (no replacement) like you would do with the traditional wheel bearings and it was fine. Not sure what type of bearing is used in the alternator.

[CTScott]

I haven't seen any info on bearings and haven't pulled one apart that far to see for myself. You might want to talk to an alternator remanufacturer and see if they can shed some light.

[barryware]

well.. I borrowed a mechanics stethoscope from a friend.. Turns out it was the water pump. The car has 72K miles on it. I replaced the water pump once @ about 38K (out of warranty) with an oem pump. This time, I bought an after market pump. We will see how this one holds up.

One bolt on the water pump is a pita..

While I have your attention.. I checked my trans fluid. It is purple (more red than purple but not red).. Is that the color it is supposed to be or should it be red? If it supposed to be red, then the purple color is coming from some black getting mixed in. That would mean time to change it.

[CTScott]

The AT fluid doesn't stay bright red very long. Mine was purplish at about 12K.

[TLyttle]

I replace alternators and water pumps, once. While the replacement is doing its job, I rebuild (change seals and/or bearings) in the old one. I just ain't that difficult. One thing I DON'T do is press a bearing! I polish the shaft until the bearing is push fit, then reassemble. When the replacement fails (they always do) I re-install my rebuilt, and it goes for many, many miles withouit trouble. In other words, I am doing what the rebuilders SHOULD be doing: custom fitting the components. They don't have the time, I do.

[barryware]

My new water pump is leaking around the shaft! Crap'ola..

So much for after market pumps.. Gotta change it again. Just in case anyone is interested, the pump is made by GMB so I would not recommend purchasing that brand. It did come with a descent gasket though.

[DAEL]

2007 Yaris Bearing spec? anyone? looking at the price of alternator, bearing replacement seems like a possibility... see http://www.youtube.com/watch?v=zl-AGOplM-8

[metalshark]

Originally Posted by DAEL

2007 Yaris Bearing spec? anyone? looking at the price of alternator, bearing replacement seems like a possibility... see http://www.youtube.com/watch?v=zl-AGOplM-8

I had real bad noise. It was louder on the alternator with a stethoscope than it was on the water pump itself. I tore down the alternator and the bearings felt like new. I then pulled the water pump and it had fluid leaking from the weep port. I had replaced the water pump 18 months ago with a rebuilt. This time I got a new life time water pump. The number on the alternator grease seal was KOYO 792. For now, the car is quiet again.